The proliferation of compact disks (discs), also known as laser disks, in the form of music as well as CD-ROM products has become extensive. In recent years, recordable compact disks such as those produced by SONY, 3M, and KODAK has grown in popularity. Further, these disks are being used for archival data storage, immediate distribution of data, and for demonstration purposes. With this recent use has grown a need to label these disks once they have been produced. This is because once produced, there is no generally available visual method for determining the contents of the disk, without reducing storage capacity below the 680 MB of data or more, without external markings.
While manufacturers of large numbers of identical disks have their labels or identifying information painted, silk-screened or printed onto the disks, e.g., a layer of adherent ink or pigment is applied to the surface of the disk, this method is generally impractical for recordable compact disk producers. For small runs or those requiring immediate availability of the disk, printing or painting based methods of labeling take too much time, incur a significant setup charge, and require special equipment. Automated disk imprinting devices may be large and cumbersome, with bulk pigmented ink supplies generally favoring long production runs.
Another known method of labeling a compact disk employs a direct printing using an ink jet system onto the surface of a disk. These systems provide a special carrier for the disk, which is printed using a conventional ink jet printing apparatus. This method suffers the shortcomings of ink jet technology, including problems with the inks used, such as smudging, running, lack of scratch resistance on the disk surface, and the like. This ink jet printing technology is also relatively slow.
Ink markers may also be used to label disks, but this is unattractive and can cause damage to the disk by breaking down the coating which protects the disk. Permanent ink markers often include solvents in the ink. As a result, manufacturers such as Avery Dennison, Avery Division, Diamond Bar Calif., produce self-adhesive labels shaped like, and designed for compact disks. Improper placement of a label on a disk, especially with the advent of high speed, e.g., ten or higher speed data transfer (with single speed data transfer defined as the rate necessary to support CD audio), and higher information density disk recording technologies, such as Digital Video Disk ("DVD"), may result in read errors, or drive motor damage due to dynamic imbalance of the disk.
Other known prior art includes: Kodaka et al, U.S. Pat. No. 5,346,654, which relates to a method for forming indicia on compact disks. This method employs a molded impression from a "mother", and does not apply an adhesive label. Lexel, U.S. Pat. No. 5,316,464, relates to a hinged structure for pressing a marking onto a compact disk, and also does not apply an adhesive label. Sugaya etal, U.S. Pat. No. 4,903,255, on the other hand, relates to an adhesive label marking system for compact disks. However, the labels are ultimately applied manually, without any apparatus for assisting in accurate placement on the disk. Hanna, U.S. Pat. No. 4,385,460, relates to an optical disk or phonorecord label having a hinged portion for individualized marking, which is apparently manually applied. Nakamura, U.S. Pat. No. 5,084,127, relates to a labeling system for 3.5 inch magnetic media encased in a rectangular plastic enclosure, and thus, while placing the labels in a desired location, do not place the label concentrically directly on the rotating media.
In U.S. Pat. No. 5,543,001, and U.S. Ser. No. 661,443, filed Jun. 11, 1996, both assigned to the same assignee as the present invention, a compact disk labeling device and method is disclosed which provides various embodiments intended to assist in the accurate placement of an adhesive label, generally bearing a pressure sensitive adhesive, to a surface of a disk.
In a preferred embodiment, the label is centered with respect to the disk by means of a tapered member, inserted through the central aperture of the label, which gradually centers the label until it is in defined position. The disk is centered by a dowel inserted all the way through the spindle hole. After the label and disk are centered, a force is applied, allowing adhesion of the label to the disk. The force may be applied, for example, by a base on which the label rests, adhesive surface upward. The base, in this case, has an aperture allowing the tapered member to pass through. The dowel extends upwardly from the tapered member, and thus may serve as a handle. The label is placed on the surface of the base, adhesive side upward, with the central aperture overlapping the aperture in the base. The disk is placed on the dowel, and rests against a shoulder at an upper portion of the tapered member, with the side to be labeled facing downward. The tip of the tapered member is pressed through the central aperture of the label and the aperture of the base, with the tapered portion exerting a lateral force to center the label with respect to the tapered member. After the label is centered, the disk, resting on the shoulder is further lowered, until it contacts the label. A force is uniformly applied which permits complete and uniform adhesion throughout the contact area between the disk and label, as compared to the device and apparatus of Japanese patent JPA 532498, where the adhesion force may cant the disk for an uneven application of the label among other deficiencies, i.e., the use of two positioning members being mandatory. The label normally has a contact adhesive, which requires a relatively low contact force to cause a strong adhesion, and thus a uniformly applied force will cause complete adhesion.
The label thus generally has a central circular hole, larger than the central aperture in the disk, so that no clearance problem will arise. A member within this central circular hole which has a largest dimension approximately equal to the diameter of the hole, will locate the center of the label. This member is preferably a tapered tip cylinder, which provides an initial taper so that the tip may be easily guided into the central hole. Further insertion will gently relocate the label with respect to the member, until the label is concentric around the cylindrical portion of the member.
The label is centered by the taper on the tapered member and its larger diameter cylinder with respect to the disk. The larger diameter cylinder is insertable through the label and, in the preferred embodiment, the aperture in the surface. When the label is in a place near the junction between the larger and small diameter cylinders, the disk lies nearly adjacent to the label, properly positioned. Pressure may then be applied on top of the disk which is centered relative to the label by the dowel inserted all the way through the spindle hole so it cannot pivot or cant relative to the spindle axis, by any suitable means, including manual pressure, pressure on a pressure plate, an automatic pressure device, a spring or weight, or other known means, forcing intimate contact between the label and the disk, thus adhering the two.
The compact disk with the newly affixed label is then removed from the device by lifting the cylindrical extension and pulling the positioning cone out of the positioning hole and the hollow core portion. Thereafter, the compact disk is lifted off cylindrical extension. If not permanently affixed, the positioning plate may be removed from the cylindrical base and used to further press the label onto the compact disk. This last step is carried out by placing the positioning plate on top of the compact disk and manually pressing the plate against the disk while the disk is lying on a substantially flat surface. A separate pressure plate may also be provided, or another compact disk employed in order to compress the label.
Preferably, the label is held and pressed flatly against the disk to avoid wrinkles. Alternatively, after suitable alignment, the label may be "rolled` onto the disk, i.e., applied to the disk by applying pressure along a chord or radius of the disk extending across the label.
Further, in order to prevent finger prints from appearing on the data surface of the compact disk, it is preferred that the pressure be manually applied centrally to the compact disk, inside the data region, or that a separate device, e.g., a plate or "dummy" compact disk be provided to apply pressure to the disk without finger contact. Of course, a user may wear gloves to avoid direct finger contact.
Generally, contact adhesives applied to labels have a strong adhesion even when applied under light pressure; the reason for care in the application of pressure is to assure that the label does not shift or curl during application and to eliminate air bubbles under the label.
It has also been proposed that a member for axially aligning the disk and the member of axially aligning the label are affixed to one another. Since the disk spindle aperture is smaller than the label central aperture, a coaxial structure having varying characteristic radii may be provided, having a first member for aligning the disk and means for selectively contacting the label and the disk after alignment. For example, the contacting means may be a spring loaded cylinder with a central spindle mounted in a plate, as for example shown in U.K. patent 2305907A to Grossman, so that the label is supported by the plate and centered by the cylinder; the disk is supported by the cylinder and centered by the spindle, and after centering of each, the disk may be lowered to contact the label by compressing the spring, to ostensibly apply uniform pressure against the force of the spring.
The spring disclosed may be a helically wound resilient element. However, this requires a two part, inner and outer cylindrical member forming a housing for the spring and two relatively movable parts so the spring can be compressed, which is not only expensive, but subject to mechanical malfunction if the spring binds or rides on one of the elements. Assembly and maintenance of the assembly is also time consuming and the helically wound spring may apply an uneven pressure between the contacting surfaces of the disk and label causing air traps therebetween resulting in a wrinkled label.
Similar spring devices are also disclosed in German Patent 196 28 678, granted Oct. 29, 1998, and WP 98/10934, published Mar. 19, 1998.
Further, the prior art devices are generally not knock-down, except for the device previously disclosed in the assignee's prior patent and application, U.S. Pat. No. 5,543,001 and U.S. Ser. No. 661,443, respectively, but even so, cannot be conveniently packaged for shipment as a unit where space requirements are at a premium.
The present invention presents a solution to all these problems.